The genus belongs to the Asteraceae family.
Plants of the Tragopogon genus are forbs growing as biennial or perennial plants. They have a strong taproot and milky sap. They generally have few branches, and those there are tend to be upright.
Their leaves are somewhat grass-like linear to linear, basal and cauline, alternate and sessile, entire, narrow, parallel-veined.
The florets of the flower heads are ligulate, bisexual, fertile. The flower heads are solitary at branch tips; the peduncles are long, naked; the involucre is cylindric or narrowly conic; the phyllaries are in one row; the receptacle are naked. Flower color varies within the genus, with some yellow species, and some bronze or purple.
The seeds, achenes, are fusiform, ribbed, with 5 to 10 more or less distinct ribs, and taper into a filiform beak ending in a small disc. The seeds are borne in a globe like that of a dandelion (Taraxacum), but larger, up to 4 or 5 cm in diameter; their pappus is in 2 rows, of free plumose bristles, the outer row rarely scale-like. The seeds are dispersed by the wind.
The Tragopogon genus is native of Europe and Asia, but several species have been introduced into North America and Australia and have spread widely there.
The Tragopogon genus is represented in North America by three introduced weedy species:
Tragopogon pratensis, the only species that grows commonly in Québec, is sometimes called John-go-to-bed-at-noon because the flower heads close at midday. It is similar to the Common Salsify (Tragopogon porrifolius) but it has a large, flat head of yellow (rather than purple) flowers; it is seldom cultivated.
Some of the commoner species of Tragopogon are known, in the regions where they are commonest, by the common names Goat's beard, the translation of Tragopogon and by Goatsbeard, Salsify or Common Salsify, without further qualification. These names are therefore inherently ambiguous, and best avoided, or reserved for the genus collectively.
The common name Goat's beard, translation of the Greek generic name Tragopogon, refers to the long, feathery, hairs on the seeds, like those of the dandelions.
In the genus Tragopogon, a plant genus consisting mostly of diploids, two new species, Tragopogon mirus and Tragopogon miscellus have evolved. The new species are allopolyploid descendants of two separate diploid parent species.
The new species were formed when one diploid species fertilized a different diploid species and produced a tetraploid offspring. This tetraploid offspring could not fertilize or be fertilized by either of it's two parent species types. It is reproductively isolated, the definition of a species.
And the Tragopogon case is just one case in many observed speciations.